TLR4 and aortic valve calcification: In aortic valve interstitial cells, rapamycin, a commonly used immunosuppressant, was described to inhibit Toll-like receptor 4 (TLR4)-induced osteogenic responses by activation of signal transducer and activator of transcription 3 (Stat3) through Akt, and to alleviate the inflammation-induced initiation and progression of calcific aortic valve disease [125].